


Genocide

by Kunoichirin



Category: Undertale (Video Game)
Genre: Split-personality disorder
Language: English
Status: Completed
Published: 2019-09-15
Updated: 2019-09-15
Packaged: 2020-10-19 07:13:58
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,380
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/20653244
Author URL: https://archiveofourown.org/users/Kunoichirin/pseuds/Kunoichirin
Summary: Sans could tell from the moment he met Frisk that she was a killer waiting to happen. He thought he could change that.He was wrong.





	Genocide

**Author's Note:**

> I've never played genocide mode, because I played the other two modes first, and just thinking about killing my friends makes me want to burn myself. Therefore, I refuse to do so. If you really want to play genocide, do it first, or else you might not want to do it anymore.

Upon the first meeting with the human, Sans could see the blatant guilt of a first time killer. She seemed afraid of the knife she held, but refused to let it go. 

Sans didn't know who she killed, or why, but he believed that if he steered her on the right path, she would see that she was a good person. 

He could tell she had a sense of humor when she laughed at his whoopee cushion in the hand prank.

"Say, human," Sans began after she stopped laughing. "What's your name?"

"I'm Frisk." She said sweetly, yet guilty.

"Well then hi Frisk." Sans greeted her. "Funny name. You don't _seem _very frisky." He grinned when she laughed again. 

"I'm just nervous. And lost. I don't exactly know my way around yet." Frisk explained. "I could really use a friend around here."

"Well everyone needs a good friend, wouldn't you say?" Sans agreed. "I can help you out, don't worry. But before that, if you don't mind, I need a favor."

"I suppose it's the least I could do. What do you need?" Frisk asked, a little eagerly. 

It was risky, but worth a shot. "You see, my brother wants nothing more than to join the royal guard. So for a long time now, he wanted to capture a human to take in." Her expression turned to horror. "Oh, no, no, no, he's not dangerous." He added quickly. "He probably won't actually take you in. You seem like a nice person. Come on, follow me."

She did, not even reluctant. Frisk seemed to trust him. 

"Oh he's coming this way! Hide behind that conveniently shaped lamp." Sans instructed. She obeyed. So far, everything seemed to be going right. 

~

Papyrus and Frisk seemed to get along very well. A few times, though, Sans had seen her observe her knife curiously, and he couldn't help but wonder if he had put his brother in danger. He might've just been paranoid, but he kept thinking her eyes were red and her shirt glitched another color whenever she observed her knife. 

Sans kept a close eye on her and watched her every move, just in case. But his brother looked to be having fun, so that was good. 

"Where did you learn to cook, by the way?" Frisk asked. 

"I learned from my good friend Undyne!" Papyrus answered proudly. "She'd teach you, too, I bet!"

Frisk thought for a moment while Papyrus talked on about how the two would get along well. Sans couldn't help but notice her glitch again. 

"Say, I have somewhere to be." Sans said, looking at an imaginary watch. "I'll see you two later." He really did have somewhere to be. Now was the time he usually went to see his other friends, but he decided to hide out and see if leaving them alone was a good idea or not. 

He teleported out of sight, but watched closely at the two talking. Papyrus was continuing his one-sided conversation with Frisk. Frisk seemed to glitch more that Sans was out of sight. It worried him a bit. 

~

Sans couldn't see through the fog, but wasn't too concerned. Frisk was probably sparing Papyrus, and everything was fine. 

He thought that every time he saw someone challenge Frisk. 

Until he went back home to Snowdin, expecting to see Papyrus there, chipper as could be, nya ha haing for no reason.

But he wasn't home. Sans didn't think too much of it at first. He went to check on Papyrus's puzzles, but none were activated. And by the looks of things, hadn't been since Frisk had last been there. 

A little concerned now, Sans left too check around town. No one had seen him in a long time. 

Now panicking, Sans walked off into the fog. He couldn't see anything at first, until...

He spotted a tattered red piece of cloth in the snow. 

Sans walked to it, and picked it up. He recognized it as his brother's scarf. Sans glanced around and noticed Papyrus's armor scattered in the snow, cracked and broken. 

_No... no, no, no, she wouldn't..._

But it had to have been her. No one had seen him since Frisk had been there. But did that mean that everyone else was dead too? 

Sans felt his eye begin to twitch to life. His whole body glitched, and a psychotic grin spread across his face. Somebody will die for this. Oh, yes, there would be consequences. 

~

Sans had been waiting for about a day when she finally showed up. Frisk showed up at the castle looking innocent but nervous. She was clutching the knife even tighter than before. 

When she saw Sans she tensed up, then relaxed. She thought he didn't know. He was playing it cool, pretending to welcoming her. After all, the element of surprise was one's greatest weapon. He'd kill her, and it would all be over. 

"Sans! I didn't expect to see you here!" She greeted him. 

"And I didn't expect to see you here so soon." Sans replied. "And by yourself." Frisk tensed up again. 

"Well, the others had things to do, but helped me out so much. They're great friends." She said, almost sadly. Sans's eye twitched. 

"Of course they were." Sans grinned. "But I was curious; did you really think I wouldn't find out, you dirty brother killer?"

Before she could react, a bone pierced her chest, and she slumped to the ground, fading into nothingness. 

When she was fully deceased, Sans didn't feel nearly as satisfied as he thought he'd be. He had avenged everyone, hadn't he? Funny, he felt like something was wrong. 

And then the doors opened again. And she was standing there, a shocked expression on her face. 

_What...?_ Sans narrowed his eyes for a second, then quickly changed his expression to his natural grin. "You know, you had me fooled for quite some time. And it's funny, because I'm not that easy to fool. I think... I just really wanted to believe I had directed you too the right path. I gave you a chance. And you used it to pull the wool over my eyes. Congratulations."

"Sans, I-"

"Don't speak, human." Sans shushed her. "I was pretty 'chilled to the bone' when I found out." He winked at her, and she gave a nervous smile. "But you must be rather 'bone tired' after working your way here." Frisk laughed a little. 

"I don't know if you're messing with me, or actually letting me prepare." She replied. 

Sans forced a grin. "Nah, I'm giving you a chance to at least fight fairly. You may not deserve it, but I'm not you." Frisk flinched. "Anyway, I've been 'dying' to see you."

Frisk didn't seem to like that one. "Sans, it wasn't me."

"Mhm, of course it wasn't. And that real knife that you're holding isn't 'real'." Sans joked. "I didn't want to break my promise I made to you, but you already shattered it, so oh well." He shrugged. "I'm ready when you are."

Frisk hesitated, but stepped forward, her hands shaking. 

"Before we begin, look out the window." Sans told her. She cautiously obeyed. "It's a beautiful day outside. Birds are singing, flowers are blooming; on days like this, kids like you..." his eye flared to life. "Should be burning in hell!"

Frisk glitched, and her eyes opened to reveal blood red eyes. A devilish smile crossed her face. "Don't worry, I'll make this quick."

_What the- it's like she's another person..._ Sans thought. She immediately lashed out at him, giving him no warning. He swiftly dodged, grinning at her shocked expression. "What, did you think I'd just stand here and take it?" Sans taunted, receiving another flurry of knife swipes. Which he dodged again. 

Frisk smirked again. "Good. That'll make this fight interesting, unlike those losers. They were too easy."

Sans's eye twitched, but he didn't break his natural expression in any other way. He shot a wave of bones at her, which she dodged most of. Several of them grazed her, drawing blood. She tried to swipe at him again, but bones popped up from ground, skewering her. 

She faded away again, and, sure enough, she was back in only a matter of minutes. 

"I can sense you have quite a bit of LOV in you." Sans said. Frisk cocked an eyebrow. "Very high. Too bad you're not very 'loving'." Frisk cracked a normal smile, and her eyes closed again. 

"Sans, please listen to me." She said calmly. 

"There's no going back on what you did, so don't even try to come up with an excuse." Sans interrupted. "We either fight, or you surrender and stay dead."

Frisk actually paused to consider it. But then she glitched again, and her red eyes gleamed. "Tempting, but no. I have a home to get back to, why should I give that up for your happiness?"

Sans smirked back. "I don't know, to make up for the morals you threw away?"

"No, I'd rather just kill you." She smiled. 

"I think I'll pass, thanks." Sans replied. Inside his heart felt torn. To think he could've ended everything the first time he met her, and then she probably wouldn't have ended up like this. But he didn't. And look where it got him. 

The battle began again, and she dodged a few more bones than last time, then jumped over the bones and attempted to hit Sans. Sans dodged, and Gastor Blastered her.

And she returned again.

And again.

And again.

This time, she dodged many attacks, and almost made contact with Sans. At least, that's what he wanted her to believe.

He paused when she squeezed her eyes shut, as if blocking something out, and threw the knife aside. She looked up at Sans with tears in her eyes, and threw her arms out wide.

"You're... sparing me? Finally. Buddy. Pal." He smiled at her. "I know it must be hard for you to make that choice. To go back on everything you worked up to. But I want you to know, I won't let it go to waste. C'mere, pal." Frisk ran into his arms and cried into his shoulder. "Did you know... I'm great at lying?" Bones came down and pierced her through again.

It took longer for her to come back.

One minute passed.

Then five.

Then ten.

_Has she given up? Did I finally win?_ No. She finally appeared again.

"Sans, please. Why won't you listen to me?" She sniffled. For a split-second, Sans felt his own guilt. He shoved it away, thinking of Papyrus. "It wasn't me. It was her."

"Uhuh, and I'm not fighting you. It's this other dude who looks exactly like me." Sans shrugged. "Now fight me or die. It's your choice, pal." Frisk cried for a few minutes, before spreading her arms wide again.

"Please. I don't want to hurt you." Frisk pleaded. Sans frowned.

"Really? And what makes me different from all those others you killed?" He countered, raising his voice to a shout. "Why do you think you can spare me like- like some _pawn_?! Why do you think you control who lives and who dies?! Why do you think I'll be spared when you didn't spare my brother, so get dunked on!!" Gastor Blasters surrounded her, and blasted her until she was dust.

Sans felt hot tears fall from his eyes. _What gives you the right to enter our world and kill everyone I loved?!_

His tears evaporated in the plasma from his eye. He wiped the other and awaited her arrival. Sans took a deep breath, and pulled himself together.

She returned, her red eyes already open, the knife in hand. "Frisk has had her turn. Now it's all me."

For the first time, Sans finally saw what Frisk was trying to say. This wasn't Frisk. This was the murderer. The girl who killed his brother. Who killed his friends. Who made him hate Frisk. Who took Frisk from him.

His eyes narrowed, and his grin became a menacing frown. "Who are you?!" He demanded.

"I'm Chara. Your worst nightmare." She said sweetly. Sans glared at her.

"Why did you kill them? They tried to be your friends, so why would betray them?" He asked quietly.

"They were Frisk's friends, not mine. I killed them because they were annoying, and it was easier that way." She answered, almost sounding bored. This infuriated Sans.

This was not a human. This was not a monster. There was something otherworldly about it. "_What_ are you?" He said, his skeletal face twisting with disgust.

"I'd rather skip the pleasantries, wouldn't you?" She sighed. Sans glared at her again.

And thus, the battles began.

She was quick and seemed in full control. She kept Sans on his toes, that was for sure. She lasted through many attacks he threw at her, including his gravity control. He'd throw her down, and she would get back up just in time.

Chara leaped at him, and he finally had a clear shot to blast her.

But every time he beat her, she'd come back, seemingly quicker than before. Or was Sans getting slower?

He certainly felt slower. He was exhausted. If he could bring Frisk back out, they could work together to get rid of Chara. But the problem was, he didn't know how. So he was stuck dodging every attack and countering.

Sans threw a fleet of bones at her, but she easily dodged them all. He summoned a circle of Gastor Blasters to shoot at her, but she dodged every beam. Bones came out of every surface but she kept _dodging_. Sans was running out of tricks and stamina. And fast.

"You know... you seem strong. But... you know what?" Chara narrowed her eyes at him. "I feel pretty good right now."

"What? Why?" Chara asked.

"Because nothing can get under a skeleton's skin!" He grinned when she glared at him. "I know, I'm pretty humerus, aren't I."

"Like your brother, I don't think so." Chara scowled.

"Well my brother is a numskull," He winked at her. "You wanna know how I know?"

"How?" She asked, crossing her arms.

"He doesn't like my hotdogs. Then again, he might just not have the STOMACH FOR IT!!" He laughed. Chara didn't look very amused at first. Then she started glitching a little. _Yes! I just have to keep it up._

"Are you done?" She scowled.

"No, I've got a ton more. A SKELE-ton!" She glitched again. "You know, I think it's funny that people tell the dead folk to rest in peace. How can anyone rest with all the coffin?" Chara glitched long enough for Sans to hear Frisk laugh. "One time, Papyrus stood by the fire for too long. He was BONE-DRY!! What a bonehead..." Frisk laughed again, almost taking over. 

"Shut up!" Chara shouted, taking another swipe at him.

"Nah, you're right. These jokes aren't even that humerus. Should I put more BACKBONE into them? These jokes are very bare boned. Then again, it is TIBIA expected that I'll get lazy, and not make a SKELE-ton of them. Dang... I'm such a bonehead." He dodged another swipe. "I'm so lazy, I'm BONE IDLE!!"

Chara was definitely glitching more than before. And she was also way angrier.

"That expression you're making is sending chills down my spine." Sans grinned, side-stepping another attempted attack. "I'm surprised you're not CHARA-ED, because you're ON FIRE!!"

Even Chara laughed at that one. It was a slightly sarcastic joke, but it was still funny.

She was glitching like crazy now, but Sans cracked himself up so hard, he didn't notice Chara lunging at him in time. But Frisk took over long enough to change the direction of the knife so it only cut open his sleeve. Sans jumped away quickly. A red scarf unwound itself from Sans's arm, and floated to the floor. Sans froze when Chara picked it up. She was still kind of in control.

Chara looked up Sans, who had frozen, afraid of what she was about to do. "Out of jokes? I guess when this scarf left, it took your funny bone with it." Sans couldn't help but snicker at that. She glared at him. "Is this all you have left of your brother? It would be a shame if someone were to lose it." She glanced at an open window. Sans froze again.

"Don't." He said, all joking aside. She smirked. Then glitched. Hope was still there. Sans forced himself to smile. "Well, then again, maybe you should keep it. The red MATCHES those firey eyes of yours." Her smile became more sincere when she glitched. Her eyes were normal again. 

Frisk looked down at the scarf and knife in her hands. She threw aside the knife, and ran into Sans's arms.

"Good to have you BACK, pal." Sans grinned, patting Frisk's back.

"Was that joke made of paper?" Sans stopped and looked down at Frisk, who was grinning up at him. "Because it was TEAR-able."

Sans burst out laughing. _Oh my gods, I'm so proud._

"Sans, I have an idea." She said suddenly. "If I die, I can always reset. So, if you kill me, I could reset everything."

"Are you sure?" Sans said sadly. "It seems rather dangerous."

"Well, you can't spell 'Frisk' without the 'risk'." Sans snickered again.

"You've certainly gotten 'friskier' since the last time we met."

"Before I go, I just want you to know..." Frisk smirked for a second. "I think you're SANS-sational." Sans doubled over laughing.

"Enough with the puns, I'm FALLING APART down here!" He laughed. Frisk picked up the knife and leveled it with her heart.

"Anything you want to say before a I go?"

"Well," Sans sighed, rolling onto his back. "I'm feeling kinda DOWN about this whole thing, but," He looked up at Frisk. "Things are LOOKING UP!!"

~

Frisk looked up at Toriel before she left. "I don't like seeing you so sad..." she said sweetly. "You're to GOAT-geous not to smile." Toriel stifled a snicker.

"Where ever did you learn these puns?" She asked, smiling.

"A friend." Frisk replied. She hugged Toriel one last time, then went out the door. "I love you, nanny." Toriel smiled after her. "Oh. Before I go, do you have any hand shockers?"

"Hm? Yes, hold on a second." 

When Toriel, she was holding a yellow hand shocker. "Why do you need it?"

"To get even with someone." With that, Frisk put it in her hand and walked into the woods.

It felt so familiar to walk down the path, since she had before. But she felt good about it, not guilty like last time. She was about to see Sans again. Her best friend. And she was going to make up for everything Chara had ever done.

It wasn't too long before she saw the short figure in the distance, his hands in his pockets, his grin as he saw her. She ran towards him, arms extended, and basically tackled him.

"Woah there- HOLY EXCREMENT!!" He shouted, jumping away from her. "You been rolling on a rug to gather static or somethin'?"

"No." She grinned at him, and held up her hand to reveal the shocker. He squinted at it, then burst out laughing. "That was for the whoopee cushion you used last time."

"Well, that was a 'shocking' way to reunite, wouldn't you say?" Now it was Frisk's turn to laugh. "You know what you just proclaimed here, though?"

"What?"

"A prank war!" Sans answered, grinning. "Better watch your back, buddy. But for now," He stuck out a hand. "Good to have you back."

Without thinking, Frisk took it with her other hand. Her eyes widened at the sound of the whoopee cushion squishing. "Hey!" Sans was already off running. "Get back here! I had _just_ gotten revenge for that!"

"Pay attention next time!" Sans called back. "My 'spark' for puns and pranks will never 'flicker' out!" He pulled out sunglasses and put them on. "I am the punmaster! Get that through your thick skull, bonehead!"

Frisk laughed, and ran after him. She sensed this time, everything was going to be better. Even if she had just started a prank war she would never win.

**Author's Note:**

> I got the idea for this story from several undertale 'Stronger Than You' parodies, so you'll find some of the lyrics used. Disclaimer: I own none of the parodies, and am only borrowing.
> 
> (P.S. I am so sorry about the terrible puns.)


End file.
